Comment se forment les vagues? - C'est pas sorcier

Well, it's the wind that is at the origin of the waves. They form very far, at sea, and we can say that a part of the wind's energy is transmitted to the water. But be careful! Contrary to what one might think, the water does not move forward. The wind's energy creates a wave that moves by itself, like the wave in this basin. It goes from one side to the other, but the water does not move forward. If the water moved forward, the plug would move forward, but it stays in place. In fact, the water only accompanies the vertical movement of the wave by drawing close circles. Look at this water molecule at the top of the ridge. Well, it follows the movement of the wave, it moves forward by descending, then it goes up by receding. In fact, between the passage of two ridges, it completes a perfect circle and it returns to the starting point. It does not move forward. And we find the same movement for all water molecules at a height roughly equal to the distance that separates two ridges of waves.